A load driver converts an AC voltage supplied from an AC power source, such as a commercial power source, into a DC voltage to supply it to a load. The load driver is mounted on a power-supply device or an illumination device, for example. One load driver includes a circuit configuration of a two-converter type for the purpose of eliminating a pulsating component (ripple noise) or the like in the AC voltage. As the load driver of the related art, for example, a power-supply device including a circuit configuration of a two-converter type is disclosed in JP-A-2010-140675.
The power-supply device disclosed in JP-A-2010-140675 includes a rectifying unit for rectifying an AC voltage from a commercial power source, a first converter unit provided at a subsequent part of the rectifying unit, and a second converter unit configured by a step-up chopper circuit provided at a subsequent part of the first converter unit. The step-up chopper circuit outputs a DC voltage stabilized at a desired voltage or current to a load unit configured by one or plural light emitting diodes.